From e37132d9975076ad61330e6f728a5fc08137bedc Mon Sep 17 00:00:00 2001
From: Evan Solomon <evan@evanalyze.com>
Date: Wed, 11 Feb 2015 13:51:41 -0800
Subject: [PATCH] Skip messages that we've already seen (based on timestamp)

Attempt to fix #153
---
 src/slack.coffee | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/slack.coffee b/src/slack.coffee
index 100980c..1bc1c87 100644
--- a/src/slack.coffee
+++ b/src/slack.coffee
@@ -7,6 +7,7 @@ Util = require 'util'
 
 class SlackBot extends Adapter
   @MAX_MESSAGE_LENGTH: 4000
+  @LAST_MESSAGE_TIMESTAMP_KEY = 'SlackLastMessageTimestamp'
 
   constructor: (robot) ->
     @robot = robot
@@ -91,6 +92,12 @@ class SlackBot extends Adapter
     process.exit 0
 
   message: (msg) =>
+    # Ignore messages we've already seen
+    lastMessageTimestamp = @robot.brain.get SlackBot.LAST_MESSAGE_TIMESTAMP_KEY
+    lastMessageTimestamp ?= -Infinity
+    return if msg.ts <= lastMessageTimestamp
+    @robot.brain.set SlackBot.LAST_MESSAGE_TIMESTAMP_KEY, msg.ts
+
     # Ignore our own messages
     return if msg.user == @self.id